Grappling free flying target objects in space involves systems which possess the following capabilities: acquiring the location of the target object's position relative to the capture mechanism, establishing and tracking the relative motion of the target and capture mechanism, effecting a timely reduction in the relative separation between the two objects and then acting to capture the target object fast enough that it is grasped by the capture mechanism before the target moves out of the way on its own or is knocked away by the capture mechanism (an event known as “tip off”). The methods by which the relative positions and motions of the capture mechanism and the target object are established and tracked and the methods by which the capture mechanism is moved into position to capture are not part of this description. In general these may be accomplished through the orbital and attitude control of the captured spacecraft and in some cases augmented with manipulator arms which provide further dexterity and speed in the final stage of approach and positioning of the capture device with respect to the spacecraft which is to be captured. All these techniques are well known to those skilled in the art.
Capture mechanisms do, however, play a part in how large the relative movement can be between the target object and the capture mechanism. The faster the capture mechanism can perform an initial capture, the greater the relative motion can be between the two objects. This is because if the mechanism acts quickly enough, the target will have less time to move out of the way. For a given mechanism, the faster it works, the faster the relative motions can be between target object and capture mechanism. Providing a capture mechanism that permits a greater relative motion between the capture mechanism and the target object has significant benefits in potentially simplifying the design of the capture spacecraft if not the client spacecraft.